$EE Cylinder ID

[Terminal_Crazy]

Evening guys,
I've not had a propper play yet with my motor as i've been on call this weekend.

However as was ildly musing i remembered i'd seen a parameter in Steveo's EEHack listing cylinder ID.
I was thinking of mapping Map vs Cyl Id to spot any trends.

Well i've just sorted a csv and found 10 cylinder Id's listed ?
45
46 47
56 57
66 67
76 77
85

The middle 8 looked quite promising but the two end ones threw me.

Any explanation on these?

Thanks
Mitch

[kur4o]

The first digit is important the second can vary.
order is like this

4*,8*,5*,8*,6*,8*,7*,8* {cyl# 1,8,4,3,6,5,7,2}
4 is current firing cylinder number #1, and the order is per brackets.

[Terminal_Crazy]

The first digit is important the second can vary.
order is like this

4*,8*,5*,8*,6*,8*,7*,8* {cyl# 1,8,4,3,6,5,7,2}
4 is current firing cylinder number #1, and the order is per brackets.

Sorry, I don't follow that, ( I do but ...)
Am I missing something or had the GM guys been smoking some weird S*** ?

As I can see so far,
4=cyl 1
5=cyl 4
6=cyl 6
7=cyl 7
8=cyl 8,3,5 or 2

This lines up with the banks of a 2 plane manifold, don't see how that would fit with anything here.


On the last log I had (Needs a Non Proprtional Font to view properly)

At Startup
Rpm 45 70 100 107 280 688 1063
Cyl Id 0 77 77 86 67 47 86 66 76 57 86 86 86 86 66 86 66 86 76 86 86 86 86 76 47 57 66 86 86 47
Cylinder 7 7 6 1 6 7 4 6 6 7 7 1 4 6 1

Consecutive logs idling
Cyl Id 86 86 86 86 47 86 77 47 86 86 47 57 86 86 57 67 86 86 67 77 86 67 86 86 67 86 77 47 86 86 86 86 77 47 86 86 47 57 86 47 86
Cylinder 1 7 1 1 4 4 6 6 7 6 6 7 1 7 1 1 4 1


Since I have no idea how many frames have been lost between each frame I've received, how would I tell which cylinders are represented by the 8x's
Why would the units column change if it doesn't represnt anything ?

Thanks
Mitch

[kur4o]

The number represent degrees between low resolution falling and rising edge.
It follows engine firing order. It is used for opti diagnostics.
If you look at an optispark wheel you will get a better understanding.

Frame lost is huge here.
At idle you need at least 50 frames per second and 400 fps at 6000 rpm.
Only direct memory access can provide that resolution, or a factory GM debug tool.

[Terminal_Crazy]

The number represent degrees between low resolution falling and rising edge.
It follows engine firing order. It is used for opti diagnostics.
If you look at an optispark wheel you will get fa better understanding.
Ok, haven’t got one to hand but presumably the leading edge of the large low res slots are 90^h^h. 45 degrees apart on the wheel so 90 crank degrees apart
And the width of the slot in degrees determines the cylinder.
Are the 4 8x slots the same width then? To distinguish these 4 cylinders.

_IF_ that’s so, why have I got 10 different values in the log?
I was going to say “timing error” but don’t we have the high res signal for that?



Frame lost is huge here.
At idle you need at least 50 frames per second and 400 fps at 6000 rpm.
Only direct memory access can provide that resolution, or a factory GM debug tool.
That's my Point.
Without any reference to a preceding frame, Can I tell which cylinder i’m Looking at?

Apologies. Not being an arse, just trying to understand it.
Thanks
Mitch

[kur4o]

To identify the same width cylinder you will need to know the previous one`s id.
Second digit can vary +-2 degree from midpoint or x4-x8. Midpoint is x6
Actually this number is high resolution counts, but I guess PCM don`t count that fast at rapid rpm change. Or there are some built in tolerance protection for pcm to through fake code.

By monitoring these cyl id you can identify bad opti signal.

[steveo]

By monitoring these cyl id you can identify bad opti signal.

can you show me what a good log vs a bad log would look like? ... eehack could do this with an algorithm

[kur4o]

Good data will be if all cyl id show 46,56,66,76,86 or 6 for second digit.

Anything between 5-7 for second digit will be acceptable.
Constant 4 or 8 for second digit will be red light.
I guess lower than 4 and higher than 8 will mean opti fail in a short time.

[Terminal_Crazy]

Evenin'
Just viewed these online of the opti disc and an interesting piece on CamaroZ28.com by GaryDoug on the opti.

The small slots relate to cylinders 1,4,6,7 so would these not be distinguished by the four 8x's ?
and the varying slots as cylinders 2,3,5 and 8?

I still can't decode half of the CylinderId's from the log then as I'm unlikely to ever see the preceeding Id.

Streveo: the last couple of logs I've looked at only had x6 or x7 (and 1 x5) but these were only at idle.

Thanks
Mitch